Testing of the performance of a fruit and vegetable
solar drying system in Iraq
Khalil E.J. Al-Juamily*, Abdul Jabbar N. Khalifa,
Tadahmun A. Yassen
College of Engineering, Al-Nahrin University, Baghdad, Iraq
email: khalilej@yahoo.com, khalilej@uruklink.net
Abstract
In this work a drying system was constructed, consisting of three parts (solar collector, solar drying cabinent,
and air blower). Two identical air solar collectors having V-corrugated absorption plates of two air passes, a
single glass cover was used. The total area of the collectors is 2.4 m
2
. The dimensions of the drying cabinet are
1 × 0.33 × 2 m (width, depth, and height). The cabinet is divided into six divisions separated by five shelves.
The distance between the shelves is 0.3 m except the upper one, which is 0.5 m from the roof. Each shelf is
0.95 × 0.3 m and is made of metallic mesh. The drying chamber walls are made of aluminum plate except the
southern side, which was fixed with glass plate having the dimensions 1 × 2 × 0.002 m. Two types of fruit and
one type of vegetables were dried during the present work. These were grapes, apricots, and beans. The moisture
content of apricot was reduced from 80 to 13% within one day and a half of drying. Moisture content of grapes
was reduced from 80 to 18% in two and a half days of drying, while that of beans was reduced from 65 to 18% in
one day only. The results show that the most effective factor on the drying rate is the temperature of the air inside
the cabinet. The effect variation of speed of air inside the drying cabinet is small and can be neglected. The
relative humidity of air exit from the cabinet was small between (25–30%) and therefore there is no need for high
velocity air inside the cabinet.
Keywords: Solar drying system; Two air passes; Grapes; Apricots and beans
1. Introduction
Using the sun to dry crops and grain is one of
the oldest and most widely used applications of
solar energy. The simplest and least expensive
technique is to allow crops to dry naturally in
the field, or to spread grain and fruit out in the
sun after harvesting. The disadvantage of
these methods is that the crops and grain are
subject to damage birds, rodents, wind, and
rain, and contamination by wind blown dust
and dirt [1]. *Corresponding author.
Desalination 209 (2007) 163–170
0011-9164/06/$– See front matter © 2006 Published by Elsevier B.V.
The Ninth Arab International Conference on Solar Energy (AICSE-9), Kingdom of Bahrain
doi:10.1016/j.desal.2007.04.026